Would be great if we had proper photos of rear machine gun position. It’s very difficult to tell from these how the canopy rotates, how the machine gun mount moves and how the armor plates are located. It does look like that rounded plate #7 was attached on top of the machine gun. It is only 1.9kg after all. Plate #6 is still very odd.
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Otherwise, it doesn’t make much sense. There’s no alignment of the frames where a continuous track allows the third section to slide into the second, nor is there a coherent hinge to enable the pivot necessary for opening, as is typical in such assemblies.
From Ki-48
The revolving canopy would also explain why armor plate 8# is concave on its upper part and not simply rectangular, precisely to allow passage of the canopy.
However, the gun would still be almost completely enclosed within the fixed canopy, which is equally narrow and seemingly mounted to a simple post mount, restricting the gun’s swiveling to the dimensions of the cockpit. In contrast to the D4Y, where not only is the entire canopy released over the gun to avoid collisions, but the gun is also mounted on a movable carriage that repositions along a transversal track, allowing the gunner to reach extreme angles without contortion.
Although, given that we know the third canopy is not over the opening and the seat is adjustable in height, it is likely that it can be raised slightly more than 20º. From side to side, I don’t think so.
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The plate 6# resembles one of the waist gunner’s armor plates on the PBY. It’s likely to cover only the left side of the gun. If we observe the illustrations, the position of the gun post appears to be off-center, to the right side, due to the space taken up by the ammunition box. Thus, this plate is effectively in the centerline, where the gunner’s head should also be. However, this arrangement would result in the arc of fire not being symmetrical; one side should cover more than the other
The description of the plate 7# states that it belongs to the “rotating windshield” (revolving canopy). Its curved shape corresponds more closely with the curvature of the canopy rather than with a typical gun shield shape. The lower semicircle is to allow passage of the gun. When the canopy opens, the plate flips upside down.
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Some months ago, @tester188 showed the account of a Ki-148 operator who said that the Ki-102 Otsu had a compartment built in the nose for the Ki-148 radio-control operator to use (at the time of July 1945).
Because of that it would seem that we would need a different Ki-102 Otsu variant in the game in order for it to have the Ki-148 missile.
However, there is a photo series of a Ki-102 Otsu being loaded with a Ki-148 missile. In these photos, it seems that there is no nose compartment, because there is no glass.
So, perhaps in earlier tests, the Ki-102 Otsu used the Ki-148 without any significant airframe modifications. In this case, it would be possible to add it to the plane in the game.
I guess the pilot had to guide the missile while flying, or maybe the person in the rear seat could somehow observe it.
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It’s quite possible for these early tests, they were merely trying to test the airframe/missile, without serious consideration as to effectiveness.
That being said, such concerns are unnecessary in War Thunder, so it should definitely receive it.
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Kawasaki Ki-102A (Kō) - Suggestions / Aircraft - War Thunder — official forum
Post made by @Grzegames
Hopefully, they’ll look at the Otsu again
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I was trying to look for the AP round again and here is what I gathered:
-AP round for the gun is mentioned in at least two primary souce and two secondary sources. A Russian source even has photo of this AP round, although it’s most likely the tank gun Type 92 APHE.
-One of those two primary sources apparently claims that an AP round was manufactured specifically for for Ho-401. However a translated production list only mentions shell and training round.
-Training round, ball or substitute round is mentioned. I’m not sure if they mean the same round. If they are, then the round is only meant to make a small puff, so the gunner can better see where it hit.
-HE round mentioned everywhere.
-In addition to HE round, one source mentions “Ho-401 Kou”. I think this might be the HE round which we already have in game. American source calls it just HO-401 High Explosive Projectile as no other name is given. That would mean the other HE round is tank gun Type 90 HE.
-Many sources claim the cartridge was direct copy of the tank gun round. There is no mention if Ho-401 could or couldn’t fire the tank gun rounds. Only possible issue seems to be the the shorter lengh of Ho-401 HE as they chopped it a centimetre or two to reduce weight.
-Type 3 HEAT round isn’t mentioned in any of these documents. Did it take that long for Allies to capture anything about it?
Any bets how many more years until Ki-102 gets bombs? Just 3 more days and it’s been in game for 11 YEARS without bombs.
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The Ho-401 HE shell is shorter. You can see how the shell can now hold more propellant compared to the round for the Type 90 cannon.
So lighter projectile + more propellant = higher muzzle velocity.
I still think this would be the ideal anti-bomber shell and cannon that Japan had, despite apparantly designed for attacking ground targets 🤔
I don’t think that AP would be useful for anything other than maybe attacking sea targets.
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Having the AP shell would be a big plus, but the Ki-102 not having bombs is a major issue…
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Next year for sure!
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Yes, that is correct. The Japanese designation is substitute shells, which are training rounds. These substitute shells are made from inexpensive railway steel bars and are filled with sand to match the projectile weight of HE shells. Substitute shells already exist as practice shells for the 20 mm Ho-5 cannon and the 37 mm Ho-204 cannon in the game.
57 mm HE Substitute Shell for Ho-401
- P - Practice shell
- Projectile Weight: 1,550 g
- Muzzle Velocity: 520 m/s
- Armour piercing (mm): 35.14
(Note: The specifications for projectile weight and muzzle velocity vary slightly depending on the source, but the highest performance data has been adopted.)
There exists an AP shell for the Ho-401, but its specifications are unknown. Therefore, I would like to suggest adding a substitute shell to the game as a literal replacement for the AP shell. The Ki-102, which often encounters lightly armored LVT amphibious tanks in the Pacific theater, should be able to sink them with HE shells and the substitute shell.
I believe that “Ho-401 Kou (ホ401甲)” is a typographical error for “Ho-401 You (ホ401用)”. “用” means “for”. In the old Japanese book I have, it was also written as “Ho-401 Kou”, but in newer publications, it has been corrected to “Ho-401 You”. It means HE shell for Ho-401.
Ho-401 Aircraft Cannon Specifications
- Manufacturer: Japan Special Steel Co., Ltd.
- Mechanism: Recoil-operated
- Caliber: 57.0 mm
- Overall Length: 2,000 mm
- Weight: 150 kg
- Muzzle Velocity: 500 m/s
- Rate of Fire: 80 rounds/min
- Recoil: 1,000 kg
- Ammunition Used:
- HE shell, HE substitute shell, and AP shell for the Ho-401
- Complete Round Weight: 2,100 g
- Projectile Weight: 1,500 g
- Mounted on Aircraft: Ki-102
- Inspection Completed: March 1944
Jiro Sayama. “Japanese Army Air Weapons.” 2021. ISBN-13: 978-4769831976. p. 616
I submitted a bug report to add substitute shells for the 37 mm Ho-203 cannon to the game based on this reasoning. Historically, the Ki-45 Kai Hei equipped with the Ho-203 was deployed not only to fighter squadrons but also to assault and light bomber squadrons for use as a ground attack aircraft. Therefore, within the game, anti-tank attack means are necessary, but it lacks general-purpose bombs and HEAT cluster bombs. Adding substitute shells in place of AP shells would be a provisional solution. I would like to submit a similar bug report regarding the Ho-401. If you have any opinions or suggestions, please let me know.
https://community.gaijin.net/issues/p/warthunder/i/1hGg9PM0LHCP
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Autocannon by Anthony G. Williams and some other source state that Ho-203 cartridge was based on those used by Type 11 Infantry Gun. Of course a lighter HE shell was developed to improve velocity, but it wasn’t enough and Ho-204 used the same shell with larger propellant. In game Ho-204 appears to be using a 600g ground use HE, while it should have 475g HEI with 32g HE filler. Right now I’m not sure about the filler type.
TM 9-1985-5 Japanese Explosive Ordnance 2 also states Ho-203 and Ho-204 used the same shell. It also mentions that all 37mm AT-guns used the same Type 94 AP round, but unfortunately it doesn’t have anything about Type 1 AP round.
雑誌 航空ファン 1997 2 No.92 イラストレイテッド 日本陸軍機 “Bunrindo Number Catalog” lists an AP round for Ho-204 with 726g projectile weight and 1236g full weight and muzzle velocity just 525m/s. The projectile weight matches Type 1 APHE. CINCPAC Bulletin 85-45 Japanese Projectiles Vol 1 has Type 1 APHE.
Ordnance Technical Intelligence Report Number 19, Ordnance Department, 13.3.1946 also lists AP round for both Ho-203 and Ho-204.
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Thank you tester!
Here are some other related issues:
Ki-102a (Ko) Fighter variant / Ki-102b (Otsu) lack of bombs // Gaijin.net // Issues
Ki-102 armor // Gaijin.net // Issues
Ki-102b lacking bombs // Gaijin.net // Issues
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anyone know if the Ki-102 otsu could carry a 800 kg bomb?
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Go ahead :)
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Since I am very slow at writing reports, could you please write the bug report? 🙂
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Hmm? It says “800 x 1” in the manual though, doesn’t it?